1. Field
The following description relates to a communication system and a communication method that use a rate split scheme.
21 . Description of Related Art
There are a variety of methods for processing/eliminating interference in a wireless communication system and a variety of methods for improving the capacity of the communication system in an environment where an interference channel exists.
For example, when the strength of an interference signal is weak, a receiver may regard the interference as a noise and may decode a received signal to extract a desired signal. Conversely, when the strength of the interference signal is strong, the receiver may decode the interference first, eliminate the interference from the received signal, and subsequently extract a desired signal.
When the strength of the interference signal is moderate, a method known as a Han-Kobayashi may be used to remove interference. According to the Han-Kobayashi method, a transmitter may split a transmission message into a common message and a private message. The transmitter may apply a superposition-coding to the common message and the private message, and may transmit the superposition-coded message. The transmitter may be have a corresponding receiver, and the common message refers to a message that is decodable in an adjacent receiver in addition to the receiver corresponding to the transmitter. The private message is a message that is decodable only in the receiver corresponding to the transmitter. A scheme of splitting the transmission message into at least two messages and then allocating different rates or different transmission powers to the at least two messages, is generally referred to as a rate split scheme.